A hybrid vehicle comprises an internal combustion thermal engine, which transmits torque to the drive wheels by means of a transmission provided with a gearbox, and at least one electric machine which is electrically connected to a storage system for the storage of electric energy and mechanically connected to the drive wheels.
The storage system for the storage of electric energy comprises a plurality of electrochemical batteries which are connected in series and in parallel. The most important feature of the storage system for the storage of electric energy for a hybrid vehicle is the weight/performance ratio, because the storage system must ideally provide high electric performance (typically the electric energy stored as a whole and the maximum deliverable electric power) being at the same time very light (and thus not very large).